I’ve attempted for months to catch a signal from the ISS as it quickly flies over head. Being in such a low-earth orbit, the longest pass you can catch is about ten minutes long. Yesterday, I was able to hear a bit of the APRS packets coming off the transmitter. Mac platforms, unfortunately, have little to offer in the way of AX.25 as of yet. Though I wasn’t quite setup, I do have an old G3 iBook (liBook?) that I’ve installed Gentoo on and configured AX.25 to work with an external audio interface. More to come.